This invention relates to a serial impact printer for multicolor printing and more particularly to a serial impact printer capable of performing multicolor printing at high speed.
A serial impact printer for multicolor printing is generally provided with an electronic memory for storing printing data for one line so as to conducting printing, after having stored the printing data for the whole line, by starting from either the right side or the left side, in order and continuously. The print head assembly is therefore moved continuously in a raster pattern without any halting or stoppage in the course of printing.
As a serial printer of this kind for performing multicolor impact printing, U.S. Pat. No. 4,073,371 is prior art wherein one color band, for example, the red band out of a multicolored inked ribbon having several color bands is selected to be printed at first in one given print line from right to left; then another color band, for example, the blue band is selected to be printed next in the same print line from right to left; and then still another color band, for example, the yellow band is selected for a similar course of printing. The printing method of selecting color bands like this in order followed by the repeated printing for a given line is disclosed in the above-mentioned patent.
This method is disadvantageous as it reduces the printing speed in comparison to ordinary monocolor, mainly black, impact printing.
This invention is aimed at providing a serial impact printer for multicolor printing, which eliminates the conventional disadvantage, and in which the color change mechanism for the multicolor inked ribbon is done away with or discarded and the printing speed is increased. The invention comprises a device which embodies a unique relative arrangement between the multicolor inked ribbon and the print head assembly. For the purpose of achieving this object, an inked ribbon in an impact printer for multicolor printing of this invention is divided into multiple colored bands each along the longitudinal direction thereof, and is arranged to extend and move in a direction intersecting the print line. A print head assembly is provided with print wire units arranged along the print line as many as the number of the above-mentioned colored bands, and each of the print wire units comprises a plurality of print wires and is disposed always in opposition to each of the colored bands respectively.
In this arrangement and method multicolored impact serial printing can be performed, just like in the conventional monocolor impact printing, without conducting the color change in the multicolor inked ribbon. In this way printing of colored graphics as well as colored letters can be carried out without decreasing the printing speed at all.